銑削壓克力之刀具幾何角度與研磨參數最佳化分析

Optimization analysis of tool geometry and grinding parameters for milling acrylics

邱瑞杰(Ruei-Jie Ciou)

指導教授 ： 李炳寅

共同指導教授 ： 陳進益

國立虎尾科技大學/工程學院/機械與電腦輔助工程系碩士班/碩士(2016年)

摘要

隨著3C電子產業的發展，手機產業隨之蓬勃發展，而手機外殼的應用也越來越多樣性，從原本塑膠材料演進為複合材料以及玻璃纖維，甚至演進成為使用壓克力(PMMA)進行製作外殼。手機外殼往往講求美觀以及輕巧性，至於美觀方面講求無刀痕以接近鏡面加工，所以在刀具上的選用就成為相當重要的課題。
本論文第一階段幾何角度設計是使用鎢鋼刀具對PMMA進行加工測試，主要利用田口直交表配置，此因田口方法能夠有效地降低所消耗費的時間與成本，而達到最高的實驗效率以及增進製程穩定性，同時各實驗因子間皆為獨立性，所以先以L9(33)直交對幾何角度進行分析，依據實驗結果再進行變異數分析，接著使用灰關聯分析結合多目標轉換為單一目標，以求達到多目標之最佳因子組合。接著使用全因子配置驗證最佳化參數組合是否具可靠性，進而分析各角度對加工PMMA所造成的各項影響。
第二階段為刀具研磨參數設定，所以使用L32(21x49)直交表規劃各因子水準作實驗，依據結果進行變異數分析，接著使用灰關聯分析結合多目標轉換為單一目標，以求達到多目標之最佳因子組合，得到刀具表面粗糙度品質以及外觀尺寸都在要求範圍內而研磨時間最短的一組研磨參數。
由第一階段實驗幾何角度設計可找出最佳化的PMMA刀具幾何參數，同時也可分析各角度對加工時所造成之影響，第二階段可得到最佳化研磨參數組合使研磨效能提升而降低生產成本。

關鍵字

田口法 ； 表面粗糙度

並列摘要

The mobile phone industry gradually grows up owing to the development of 3C electronics industry. Housings of mobile phones have a great diversity of applications and the plastic material change to composite material, glass fiber, or acrylic (PMMA). End users often pursue the lightweight housings and beautiful appearance that is similar to the mirror finish without milling marks. Therefore, the use of cutting tools becomes a very important issue.
In this thesis, the first stage of the geometry design was to employ Taguchi orthogonal array and tungsten carbide cutting tool for processing test of PMMA due to this method can effectively reduce the time and cost, achieve the high efficiency, and improve the stability of the process. At the same time, the experimental control factors were all independent, so we applied the L9 orthogonal array to analyze the geometric angles of the cutting tools. Based on the experimental results, in order to obtain the optimal combination of the factors, the analysis of variance and the grey relational analysis were adopted to change from the multiple objectives to a single objective. Then, the full factorial design was utilized to verify the reliability of the optimal combination of parameter values, and analyze the influence of the geometric angles for processing of PMMA.
The second stage was the setting of the grinding parameters by using the L32 orthogonal array for each level of the control factors. According to the results of the analysis of variance and the grey relational analysis, one can converter the multiple objectives to a single objective to obtain the optimal combination of the factors. Thus, the surface roughness of the cutting tools and the geometric profiles were controlled inside the required tolerance range, and the grinding time was shortest.
From the first stage, we can find the optimal geometric angles of the cutting tools and the influence for milling PMMA. Furthermore, the optimal grinding parameters can improve the efficiency and reduce the manufacturing cost by the second stage.

並列關鍵字

Taguchi method ； surface roughness

參考文獻

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